1 /*******************************************************************************
2 *
3 * Module Name: nsnames - Name manipulation and search
4 *
5 ******************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2012, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "amlcode.h"
47 #include "acnamesp.h"
48
49 #define _COMPONENT ACPI_NAMESPACE
50 ACPI_MODULE_NAME("nsnames")
51
52 /*******************************************************************************
53 *
54 * FUNCTION: acpi_ns_build_external_path
55 *
56 * PARAMETERS: Node - NS node whose pathname is needed
57 * Size - Size of the pathname
58 * *name_buffer - Where to return the pathname
59 *
60 * RETURN: Status
61 * Places the pathname into the name_buffer, in external format
62 * (name segments separated by path separators)
63 *
64 * DESCRIPTION: Generate a full pathaname
65 *
66 ******************************************************************************/
67 acpi_status
acpi_ns_build_external_path(struct acpi_namespace_node * node,acpi_size size,char * name_buffer)68 acpi_ns_build_external_path(struct acpi_namespace_node *node,
69 acpi_size size, char *name_buffer)
70 {
71 acpi_size index;
72 struct acpi_namespace_node *parent_node;
73
74 ACPI_FUNCTION_ENTRY();
75
76 /* Special case for root */
77
78 index = size - 1;
79 if (index < ACPI_NAME_SIZE) {
80 name_buffer[0] = AML_ROOT_PREFIX;
81 name_buffer[1] = 0;
82 return (AE_OK);
83 }
84
85 /* Store terminator byte, then build name backwards */
86
87 parent_node = node;
88 name_buffer[index] = 0;
89
90 while ((index > ACPI_NAME_SIZE) && (parent_node != acpi_gbl_root_node)) {
91 index -= ACPI_NAME_SIZE;
92
93 /* Put the name into the buffer */
94
95 ACPI_MOVE_32_TO_32((name_buffer + index), &parent_node->name);
96 parent_node = parent_node->parent;
97
98 /* Prefix name with the path separator */
99
100 index--;
101 name_buffer[index] = ACPI_PATH_SEPARATOR;
102 }
103
104 /* Overwrite final separator with the root prefix character */
105
106 name_buffer[index] = AML_ROOT_PREFIX;
107
108 if (index != 0) {
109 ACPI_ERROR((AE_INFO,
110 "Could not construct external pathname; index=%u, size=%u, Path=%s",
111 (u32) index, (u32) size, &name_buffer[size]));
112
113 return (AE_BAD_PARAMETER);
114 }
115
116 return (AE_OK);
117 }
118
119 /*******************************************************************************
120 *
121 * FUNCTION: acpi_ns_get_external_pathname
122 *
123 * PARAMETERS: Node - Namespace node whose pathname is needed
124 *
125 * RETURN: Pointer to storage containing the fully qualified name of
126 * the node, In external format (name segments separated by path
127 * separators.)
128 *
129 * DESCRIPTION: Used for debug printing in acpi_ns_search_table().
130 *
131 ******************************************************************************/
132
acpi_ns_get_external_pathname(struct acpi_namespace_node * node)133 char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
134 {
135 acpi_status status;
136 char *name_buffer;
137 acpi_size size;
138
139 ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
140
141 /* Calculate required buffer size based on depth below root */
142
143 size = acpi_ns_get_pathname_length(node);
144 if (!size) {
145 return_PTR(NULL);
146 }
147
148 /* Allocate a buffer to be returned to caller */
149
150 name_buffer = ACPI_ALLOCATE_ZEROED(size);
151 if (!name_buffer) {
152 ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
153 return_PTR(NULL);
154 }
155
156 /* Build the path in the allocated buffer */
157
158 status = acpi_ns_build_external_path(node, size, name_buffer);
159 if (ACPI_FAILURE(status)) {
160 ACPI_FREE(name_buffer);
161 return_PTR(NULL);
162 }
163
164 return_PTR(name_buffer);
165 }
166
167 /*******************************************************************************
168 *
169 * FUNCTION: acpi_ns_get_pathname_length
170 *
171 * PARAMETERS: Node - Namespace node
172 *
173 * RETURN: Length of path, including prefix
174 *
175 * DESCRIPTION: Get the length of the pathname string for this node
176 *
177 ******************************************************************************/
178
acpi_ns_get_pathname_length(struct acpi_namespace_node * node)179 acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
180 {
181 acpi_size size;
182 struct acpi_namespace_node *next_node;
183
184 ACPI_FUNCTION_ENTRY();
185
186 /*
187 * Compute length of pathname as 5 * number of name segments.
188 * Go back up the parent tree to the root
189 */
190 size = 0;
191 next_node = node;
192
193 while (next_node && (next_node != acpi_gbl_root_node)) {
194 if (ACPI_GET_DESCRIPTOR_TYPE(next_node) != ACPI_DESC_TYPE_NAMED) {
195 ACPI_ERROR((AE_INFO,
196 "Invalid Namespace Node (%p) while traversing namespace",
197 next_node));
198 return 0;
199 }
200 size += ACPI_PATH_SEGMENT_LENGTH;
201 next_node = next_node->parent;
202 }
203
204 if (!size) {
205 size = 1; /* Root node case */
206 }
207
208 return (size + 1); /* +1 for null string terminator */
209 }
210
211 /*******************************************************************************
212 *
213 * FUNCTION: acpi_ns_handle_to_pathname
214 *
215 * PARAMETERS: target_handle - Handle of named object whose name is
216 * to be found
217 * Buffer - Where the pathname is returned
218 *
219 * RETURN: Status, Buffer is filled with pathname if status is AE_OK
220 *
221 * DESCRIPTION: Build and return a full namespace pathname
222 *
223 ******************************************************************************/
224
225 acpi_status
acpi_ns_handle_to_pathname(acpi_handle target_handle,struct acpi_buffer * buffer)226 acpi_ns_handle_to_pathname(acpi_handle target_handle,
227 struct acpi_buffer * buffer)
228 {
229 acpi_status status;
230 struct acpi_namespace_node *node;
231 acpi_size required_size;
232
233 ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
234
235 node = acpi_ns_validate_handle(target_handle);
236 if (!node) {
237 return_ACPI_STATUS(AE_BAD_PARAMETER);
238 }
239
240 /* Determine size required for the caller buffer */
241
242 required_size = acpi_ns_get_pathname_length(node);
243 if (!required_size) {
244 return_ACPI_STATUS(AE_BAD_PARAMETER);
245 }
246
247 /* Validate/Allocate/Clear caller buffer */
248
249 status = acpi_ut_initialize_buffer(buffer, required_size);
250 if (ACPI_FAILURE(status)) {
251 return_ACPI_STATUS(status);
252 }
253
254 /* Build the path in the caller buffer */
255
256 status =
257 acpi_ns_build_external_path(node, required_size, buffer->pointer);
258 if (ACPI_FAILURE(status)) {
259 return_ACPI_STATUS(status);
260 }
261
262 ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
263 (char *)buffer->pointer, (u32) required_size));
264 return_ACPI_STATUS(AE_OK);
265 }
266